Drought in California
The state of California is experiencing one of the worst droughts in recorded history as record low precipitation, high temperatures and low moisture impact negatively on the water security of the state (Griffin and Anchukaitis, 9018). The drought, which began in 2012 when the state experienced relatively high dry conditions, peaked in 2014 when there was extreme aridity. By September 2014, there was a state of exceptional drought across most of California with most of the state experiencing record lows of precipitation levels (Griffin and Anchukaitis, 9019). Droughts in California are not a new phenomenon, and the history of the state is littered with periods of drought over the past centuries. However, the frequency of drought years over the past two decades has been much higher than the observed frequency in the preceding century (Diffenbaugh, Swain, and Touma, 3931). The increase in the frequency of drought years suggests that there are unique circumstances in the recent past, which may have contributed to the rising probability of drought years in the state.
Recent research suggests that anthropogenic warming may be contributing to the rising frequency in drought years in the state (Diffenbaugh, Swain, and Touma, 3932). Records in California show that there has been no substantial change in the occurrence of years of low or moderately low rainfall despite the current increase drought risk. Although the precipitation levels have remained relatively stable over the years, there has been an increase in drought frequency over the same period, implying that precipitation levels cannot predict the probability of drought in isolation. What changed dramatically in the past two decades is the average temperatures recorded across the state. The average temperatures have been increasing steadily, and some of the warmest years in the state have been recorded in the past two decades. Increase in average temperatures has a significant impact on the rate of water loss from the ground through evaporation and transpiration in plants. Therefore, even though the precipitation levels are kept constant, increased temperatures lead to faster water loss, causing the ground to be parched faster than when the temperatures are lower.
Anthropogenic warming is having a detrimental effect on the extent of the Sierra snowpack, with a recent measurement 1st April 2015 showing that the snowpack was at five percent of the average April first level (The California drought, n.p.).The level of the snowpack at 1st April is crucial to the water safety of California because at this time, the pack is at its peak, and the subsequent melting of the snow and runoff into rivers provides approximately one-third of the water used by Californians. The record low levels of the snowpack imply that there will be a limited amount of snow melting and running off into rivers hence the river levels are likely to be lower than normal. This means that the amount of water available for Californians is likely to be limited in the near future. The scarcity of water has made the Californian government to institute conservation measures in a bid to reduce the water consumption of residents. Some of the measures that the state has implemented include the rationing of water to residents, requiring neighborhoods to cut their water usage by set percentages (Nagourney and Healy, n.p.). Neighborhoods with the highest usage are required to cut their usage by the largest levels while those that are using lower volumes need to cut their usage levels by lower percentages.
The introduction of a tiered pricing system is seen as one of the ways to discourage wastage and encourage heavy users of water to substantially cut back on their usage (Nagourney and Healy, n.p.). Heavy users are charged more for water compared to lighter users, with the hope that the punitive charges for excessive consumption will persuade the heavy users to cut back on their consumption and hence reduce the strain on the water supply system. The water security for California remains precarious in the short to medium-term and there is an urgent need to intensify the conservation efforts because if the usage is not capped, the environmental effect of water usage is likely to be devastating. Demand for water has long been outstripping supply in California, and this is likely to get worse as the water sources dry up and produce lesser volumes of water. However, it is important to note that although households are significant consumes of water in California, farmers are by far the biggest consumers of water, consuming over two thirds of the water in California.
Farming in California is largely irrigation dependant, implying that farmers require vast amounts of water to grow their crops and remain in business. With the reduction in the levels of available surface water, farmers have resorted to using other means to obtain the water that is crucial to their business. There has been an increase in the extraction of underground water through boreholes, with farmers drilling wells at an unprecedented rate (Martin, n.p.). The extraction o ground water is at a rate that is higher than it can be naturally replenished, and boreholes are becoming deeper and deeper to reach the water table. The increased extraction of water from the underground has led to the sinking of California’s central valley, a phenomenon, which is now being observed on the ground. The rapid removal of water from the ground causes the ground to shift downwards to fill the space created by evacuation of water. Consequently, non-elastic ground infrastructure like roads, canals and pipelines, among others is at risk to land subsidence. The sinking land is causing loads to crack and pipelines to burst, placing an economic burden on the state, which has to repair the damaged infrastructure.
though extraction of underground water can help in ameliorating the water
shortage in the short-term, unsustainable extraction of ground water is likely
to cause further environmental damage. In addition, there is danger that some
of the underground water reservoirs are likely to be invaded by saline water because
the rapid removal of the underground water does not allow for natural
replenishment. The chances of the Californian water cycle reaching equilibrium
in the short term are at best faint considering the confluence of factors that
are exacerbating the situation. Anthropological warming is likely to be a
continuing concern as the global fight against anthropological warming is severely
hampered by entrenched interests, which are resisting the implementation of
mitigation measures that could ameliorate the effect of anthropological
warming. The water demand of California is projected to keep rising in the long
term as population increase places more pressure on the supply system.
Diffenbaugh, Noah, Daniel L. Swain, and Danielle Touma. “Anthropogenic warming has increased drought risk in California.” PNAS, 112.13, 3931-3936. (2015). Print.
Griffin, Daniel, and Kevin J. Anchukaitis. “How unusual is the 2012–2014 California drought?” Geophysical Research Letters, 41,9017–9023. (2014). Print.
Martin, Allen. “California’s Central Valley Sinking Faster than Ever Before as Farmers Drill for Water During Drought” CBS. 26 April 2015. [Online]. Accessed 27 April 2015 < http://sanfrancisco.cbslocal.com/2015/04/26/californias-central-valley-sinking-faster-than-ever-before-as-farmers-drill-for-water-during-drought/>
Nagourney, Adam and Healy Jack. “Drought Frames Economic Divide of Californians.” The New York Times. 26 April 2015. [Online]. Accessed 27 April 2015 <http://www.nytimes.com/2015/04/27/us/drought-widens-economic-divide-for-californians.html?_r=0>
The California Drought. U.S. Geological Survey.1 April 2015. [Online]. Accessed 27 April 2015 < http://ca.water.usgs.gov/data/drought/>